This invention relates to a speed change lever for bicycles, and more particularly to improvements in a mounting structure for fixing the lever to a bicycle frame tube.
As is well known, the speed change lever is utilized to control a running speed of a bicycle which is equipped with a multiple freewheel (rear gear) having a plurality of different sized sprockets cooperating with a rear derailleur, wherein the bicycle speed change is generally performed by pulling or releasing a tensioned flexible control cable, which is operatively connected at its one end to a lever handle and at its other end to the rear derailleur, so that an endless drive chain can be selectively shifted from one sprocket to another sprocket of the multiple freewheel to change gear ratio.
In a particular type of bicycle which is equipped, in addition to the multiple freewheel, with a multiple chainwheel (front gear) having a plurality of different sized sprockets cooperating with a front derailleur, an additional speed change lever is required to control a bicycle running speed by pulling or releasing an additional tensioned flexible control cable, which is operatively connected at its one end to an additional lever handle and at its other end to the front derailleur, so that the endless drive chain can be selectively shifted from one sprocket to another sprocket of the multiple chainwheel to change gear ratio. Thus, this particular type of bicycle is equipped with a pair of speed change levers and a pair of control cables, namely, the first lever cooperating with the first cable to control the rear derailleur, and the second lever cooperating with the second cable to control the front derailleur. The pair of levers are usually mounted on a bicycle frame tube in a symmetrical fashion (See FIG. 2).
It is known to mount the speed change lever on a bicycle frame tube by means of a detachable clamp band or a lever mount weldable to the frame tube.
A typical example of the conventional lever, that is, the lever having the clamp band, is disclosed as Model LD-2900 in "SUNTOUR SMALL PARTS CATALOG" of February, 1983 published by the Applicant of the present invention.
For better understanding, the aforesaid model is herein illustrated in FIG. 5 of the accompanying drawings, in which a clamp band 2 is fixed to a bicycle frame tube F (e.g. a down tube) by means of a clamp screw 18 and a nut 19.
A lever support spindle 3 is fixedly connected at its one end 1 to the clamp band 2 by caulking, together with a base plate 7. The stationary support spindle 3 has an annular flange 3a disposed on the base plate 7. The free end portion of the spindle shank 3b is partially cut off at opposite sides thereof to provide a pair of flat engaging surfaces 3c. The spindle 3 has an axial threaded hole 8 which is engageable with a threaded shank of a lock bolt 14.
A lever handle 4 to be rotatably mounted at its holed end portion 5 onto the support spindle 3 has an outside seating recess 9 defined by an internal cylindrical wall and an outward facing annular wall as illustrated, an inside seating recess which is not shown but substantially identical in form to the aforesaid outside seating recess, and a through hole 6 interposed between the inside and the outside seating recesses in communication therewith.
The lever handle 4 is mounted on the support spindle 3 in such a manner that the annular flange 3a is seated in the inside seating recess while the spindle shank 3b extends through the through hole 6 so that the shank end formed with the flat engaging surfaces 3c projects out of the hole 6 into engagement with a correspondingly shaped center hole 10 of an outside washer 11, resulting in that the washer 11 is non rotatably seated in the outside seating recess 9 and sandwiched between the outward facing annular wall and a cover disk 12. An inside washer 20 is sandwiched between the annular flange 3a and an inward facing annular wall (not shown) of the inside seating recess.
The base plate 7 has an arm 16 extending in parallel with the spindle 3. The free end of the arm 16 is formed with a notch 17 which is engageable with a mating projection 15 of the cover disk 12 for preventing the latter from rotation. Thus, as will be easily understood, all of the base plate 7, the spindle 3, the outside washer 11 and the cover disk 12 are prevented from rotation.
The threaded shank of the lock bolt 14 extends through each hole of the holed members, that is, the cover disk 12, the outside washer 10, the lever handle 4, and the inside washer 20 into the threaded hole 8 of the spindle 3, when they are assembled together.
Thus, by adjustably tightening the lock bolt 14, the lever handle 4 can be held in any selected position on the spindle 3 by adjusted frictional force applied to the opposite sides of the portion 5 thereof but is rotatable on the spindle 3 against the applied firctional force as well as a tension force applied by the control cable when the lever handle 4 is manipulated by a cyclist.
Another typical example of the convertional lever, that is, the lever having a lever mount weldable to a bicycle frame tube, is also disclosed as Model LD-2950 in the above-mentioned catalog of the Applicant, in which a lever support spindle is integral with and extends from the lever mount for supporting a lever handle and various other small parts such as washers thereon.
As will be easily understood from the foregoing description with reference to FIG. 5, the bicycle speed change lever includes various small independent parts which are to be assembled in prescribed order. Therefore, the conventional bicycle lever has the following disadvantages:
The first disadvantage is that it takes a considerable time to assemble various small independent parts for the lever one by one in prescribed order, which causes inefficiency in the process for mounting the lever to a bicycle frame tube in the manufacture of bicycles;
The second disadvantage is that stock control of an asortment of various small independent parts for the lever is troublesome; and
The third disadvantage is that, when the lock bolt is unexpectedly removed in use, many of the small independent parts are likely to scatter, with the result that one or more of the small parts may occasionally be lost, which is very inconvenient to an end user because the lost parts are not readily available to him.
It is, therefore, an object of the invention to provide an improved bicycle speed change lever which can be easily and quickly mounted onto a bicycle frame tube.
Another object of the invention is to provide an improved bicycle speed change lever which permits easy stock control and assortment of parts therefor.
A further object of the invention is to provide an improved bicycle speed change lever which can be assembled together so that small independent parts therefor will not easily scatter when a lock bolt is unexpectedly removed in use.
Other objects, features and advantages of the invention will become apparent from the detailed description given hereinafter; it should be understood, however, that the detailed description and specific examples, while indicating preferred embodiments of the invention, are given by way of illustration only, since various changes and modifications within the spirit and scope of the invention will become obvious to those skilled in the art from this detailed description.
According to the present invention, there is provided a bicycle speed change lever comprising: a stationary support spindle which has an axial threaded hole formed therein and an integral base portion formed therewith so as to be weldable to a bicycle frame tube, a lever handle rotatably mounted at its holed end portion on the support spindle, a plurality of washers supported on the lever spindle, a clipping holder which has a pair of axially spaced disk-like portions resiliently connected to an integral cross arm and which is non-rotatably mounted on the spindle, with the washers and the holed end portion of the lever handle sandwiched between the pair of disk-like portions, to hold them together by pressure, and a lock bolt having its threaded shank extending through each hole of the holed members supported on the spindle into engagement with the threaded hole of the spindle.